US4620153A - Magnetic resonance imaging system - Google Patents

Magnetic resonance imaging system Download PDF

Info

Publication number
US4620153A
US4620153A US06/661,459 US66145984A US4620153A US 4620153 A US4620153 A US 4620153A US 66145984 A US66145984 A US 66145984A US 4620153 A US4620153 A US 4620153A
Authority
US
United States
Prior art keywords
starting point
reconstruction
data
register
correction coefficient
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US06/661,459
Other languages
English (en)
Inventor
Masaaki Hino
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp filed Critical Toshiba Corp
Assigned to KABUSHIKI KAISHA TOSHIBA, A CORP. OF JAPAN reassignment KABUSHIKI KAISHA TOSHIBA, A CORP. OF JAPAN ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: HINO, MASAAKI
Application granted granted Critical
Publication of US4620153A publication Critical patent/US4620153A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/44—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using nuclear magnetic resonance [NMR]
    • G01R33/48—NMR imaging systems
    • G01R33/54—Signal processing systems, e.g. using pulse sequences ; Generation or control of pulse sequences; Operator console

Definitions

  • the present invention relates to a magnetic resonance imaging (MRI) system in which a measuring technique utilizing the magnetic resonance (MR) phenomenon is adopted in a computed tomography (CT) technique and, more particularly, to a fast reconstruction technique for obtaining a reconstructed image in a short time in a system in which a back projection method is adopted in image reconstruction.
  • MRI magnetic resonance imaging
  • CT computed tomography
  • the MR phenomenon occurs in an object to be examined, and a magnetic wave which is excited by the MR phenomenon is detected as an MR signal.
  • projection data in which resonance data of specific nucleus is projected on a specific slice of the object to be examined can be obtained in many directions.
  • image data representing at least one of a spin density of the specific nucleus and a relaxation time constant can be obtained.
  • MRI magnetic resonance imaging
  • an MRI system comprising a means for performing image reconstruction processing which comprises:
  • a central processing unit for generating data of a reconstruction starting point of projection data about a first line parallel to a second direction in a reconstruction image matrix in which coordinate axes consist of a first direction corresponding to a direction parallel to a projection angle reference direction and the second direction perpendicular to the first direction, and data of a sampling interval and data of a predetermined correction coefficient value of the projection data along the first and second directions for every projection;
  • a constant data generating circuit for sequentially generating respective data of the sampling interval for the second direction and the correction coefficient value for every projection and for generating the reconstruction starting point data of respective lines aligned along the first direction and parallel to the second direction in correspondence to the reconstruction starting point of the first line parallel to the second direction, and the sampling intervals for the first and second directions and the correction coefficient value provided from the central processing unit;
  • a reconstructor in which reconstruction sampling positions of the projection data along a line direction parallel to the second direction corresponding to the reconstruction starting points are obtained by simply adding the sampling intervals to the respective reconstruction starting points in correspondence with the data of the sampling interval for the second direction and the correction coefficient values and reconstruction starting points of the respective lines parallel to the second direction in the reconstruction image matrix which are supplied from the constant generating circuit, thereby performing back projection on the reconstruction image matrix about the sampling positions;
  • timing controlling unit for generating a control signal to the constant generating circuit, the reconstructor and the image memory for determining an operation timing.
  • FIG. 1 is a view for explaining a principle of image reconstruction according to a back projection method
  • FIG. 2 is a view for explaining a principle of back projection image reconstruction according to an embodiment of the present invention
  • FIG. 3 is a block diagram showing a construction of a main part of an MRI system according to the embodiment of the present invention.
  • FIG. 4 is a block diagram showing the construction of the main part shown in FIG. 3 in more detail.
  • FIG. 5 is a flow chart showing an example of an operation sequence shown in FIG. 3.
  • Back projection processing is to obtain an image f (x, y) in an original space by projection data q (S, ⁇ ) after filter correction.
  • the present invention has been made in consideration of this.
  • the reconstructor and image memory in the FRU of the XCT system can also be used in the MRI system with substantially no modification.
  • the FRU of the MRI system can be realized without requiring a complex construction, and at the same time, low cost can be achieved.
  • back projection as expressed by the following equation is made in the original space in correspondence to a reconstruction starting point Sna with respect to a line direction (e.g., the X-direction of the image matrix) of the projection data and a sampling interval along the line direction:
  • DPBR.sub.(x, y) is back projection data with respect to the point (x, y) in the original space
  • DCEN.sub.(x, y) is the projection data which is subjected to various processes determined by Sna and ⁇ Xa and is further converted into the data of the parallel beam
  • ⁇ a is a correction coefficient value of the projection data
  • 1 is a interpolation constant determined by Sna and ⁇ Xa which is corresponding to ⁇ in equation (3)
  • k is an address of a projection data memory determined by Sna and ⁇ Xa.
  • a memory for storing the projection data for calculating in accordance with equation (4) is provided.
  • An address of the memory is selected by k and k+1. 1 and k are determined by Sna (n: line number, a: projection number) and ⁇ Xa (a: projection number).
  • the respective reconstruction sampling point (position) k can be obtained in the following equation by the reconstruction starting point Sna and the sampling interval ⁇ Xa.
  • k corresponds to an integral part when the sampling interval of the projection data is normalized as "1”
  • 1 corresponds to a decimal part thereof.
  • Sk is 16-bit data and upper 10 bits thereof are the integral part
  • 1 corresponds to lower 6 bits
  • k corresponds to upper 10 bits.
  • the projection data is regarded as data by the parallel beam as described above, and the principle will be described with reference to FIG. 2.
  • a reconstruction starting point S0a of the 0th line as a reference of reconstruction calculation is obtained by the following equations:
  • S0a is the reconstruction starting point of the 0th line of ath projection
  • M is a matrix size
  • ⁇ x and ⁇ y are respectively pixel sizes (mm)
  • N is the number of data samples
  • ts is a data sampling interval ( ⁇ s)
  • G is a constant corresponding to an inclined magnetic field strength for MR projection (Hz/cm)
  • C is a constant corresponding to the reconstruction matrix
  • ⁇ a is a projection angle.
  • the present invention has been made in accordance with the condition of equation (12).
  • coordinate conversion is performed such that the Y-direction, not the X-direction, corresponds to the line direction, as shown in FIG. 2.
  • processing only by positive addition can be performed as in the following equation. Therefore, the reconstructor of the XCT system can be utilized in the MRI system. ##EQU6##
  • Equation (13) corresponds to equation (5) in the case of the XCT system. Therefore, in this case, the reconstructor calculates equation (13), and back projection processing as in equation (4) is performed in accordance with the calculation result.
  • equation (14) calculation of equation (14) is made and, when Sna, ⁇ Ya and ⁇ a are given to the reconstructor of the FRU in the XCT system, image reconstruction can be performed in a short time.
  • Equation (15) can be calculated in advance by the host CPU.
  • FIG. 3 shows a configuration of the FRU for the MRI system according to the embodiment of the present invention in accordance with this principle.
  • the FRU for the MRI system comprises a selector channel Ch for coupling to the host CPU; a controller CNT having a control sequencer, a bus driver and the like; a constant generating circuit CGC; a back projection image reconstructor BPR having the same construction as that in the XCT system as described above, and an image memory IMEM having the same construction as that in the XCT system.
  • the FRU when a predetermined command is supplied to the controller CNT from the host CPU of the MRI system, the FRU is sequentially operated, thereby performing reconstruction for one line of an image. Furthermore, the FRU is connected to the host CPU by the channel CH and data transmission between the FRU, and a main memory of the MRI system is performed by a direct memory access (DMA) bus indendently of the CPU. Therefore, a load of the CPU is reduced, thereby improving the system efficiency of the MRI system.
  • the image memory IMEM has another function of adding reconstruction data of respective projections, and the obtained sum is stored therein as image data.
  • the image memory IMEM has a storing area corresponding to respective pixels of the image matrix (stored contents in the storing area corresponding to these respective pixels are reset when the reconstruction processing starts), and the reconstruction data which is back-projected to the respective pixels by the reconstructor BPR is accumulated for every pixels and stored therein.
  • the maximum image matrix size is 512 ⁇ 512.
  • the maximum image matrix size can also be regarded as 512 ⁇ 512. For this reason, an image memory for the XCT system can be utilized in the MRI system.
  • FIG. 4 shows the constant generating circuit CGC in more detail.
  • a data buffer 1 is a buffer memory for the projection data. A timing shift between the constant generating circuit CGC and the reconstructor BPR is corrected by this data buffer 1.
  • the data buffer 1 has a memory capacity for at least two projections.
  • a constants buffer 2 is a buffer memory for respective constants. This constant buffer 2 has a capacity for storing data of at least 300 projections.
  • a read-only memory (ROM) sequencer 3 consisting of a ROM, sequence control information which directly corresponds to control signals for controlling the respective constant output timing is programed as data in the ROM.
  • Constant registers 4 to 9 are respectively output registers of the constants Sna, ⁇ Ya and ⁇ a.
  • the constant registers 4 and 5 are respectively used as Sna registers
  • the constant registers 6 and 7 are respectively used as ⁇ Ya registers
  • the constant registers 8 and 9 are respectively used as ⁇ a registers.
  • ⁇ Xa registers 10 and 11 are necessary for the adding operation.
  • An adder 12 for accumulation has a bit length of the required bit number +8 bits to perform a maximum of 512 adding operations.
  • Gates 13 and 14 are provided to prevent the outputs of the adder 12 and the constant buffer 2 from being simultaneously supplied to the respective registers 4 to 11. These gates 13 and 14 are controlled by the ROM sequencer 3 and one of the outputs of the adder 12, and the constant buffer 2 is selected in accordance with their operations.
  • the constant registers 4 to 9 are provided such that the constants Sna, ⁇ Ya and ⁇ a are respectively stored in two of the registers 4 to 9.
  • the capacity of the data buffer 1 enables storage of the back projection data for a maximum of two projections.
  • duplex of pipe-line processing can be performed using two reconstructors in parallel.
  • This construction in which duplex of the pipe-line processing can be performed is one of characteristics features of the present invention.
  • the reconstructing operation with respect to the two projections can be performed in parallel.
  • image reconstruction can be completed in about half the time. For this reason, operation efficiency of the MRI system can be improved.
  • the constant registers 4 and 5 are the Sna registers
  • the constant registers 6 and 7 are the ⁇ Ya registers
  • the constant registers 8 and 9 are the ⁇ a registers.
  • the I/O operation of these registers 4 to 9 is controlled by the ROM sequencer 3.
  • the constants for one frame of an image are transferred to the constant buffer 2 from the host CPU.
  • the projection data is transferred to the data buffer 1 from the host CPU for every projection.
  • the projection data for one projection is transferred to the reconstructor BPR from the data buffer 1.
  • the constants S0a, ⁇ Ya, ⁇ a and ⁇ Xa are respectively transferred to the constant registers 4, 6 and 8 and the ⁇ Xa register 10 from the constants buffer 2.
  • S0a, ⁇ Ya, ⁇ a and ⁇ Xa are respectively generated from these constant registers 4, 6 and 8 and the ⁇ Xa register 10.
  • These outputs S0a, ⁇ Ya, ⁇ a and ⁇ Xa are transferred to the reconstructor BPR and the outputs S0a and ⁇ Xa are respectively supplied to the adder 12.
  • the constants S0a and ⁇ Xa are added to each other by the adder 12.
  • the updated constant S1a is latched by the constant register 4 for holding Sna.
  • the output S1a is generated from the constant register 4 and is supplied to the reconstructor BPR.
  • the output S1a and the output ⁇ Xa from the ⁇ Xa register 10 are added to each other by the adder 12.
  • the sum S2a is latched by the constant register 4 for holding Sna. In this manner, the reconstruction starting points Sna of the respective lines can be sequentially calculated without requiring complex calculation, and these sums Sna are sequentially supplied to the reconstructor BPR.
  • the calculation is simplified by sufficiently utilizing the characteristic that the projection in the MRI system is regarded the same as that by the parallel beam.
  • the constants for one frame of an image are transferred to the constant buffer 2 from the host CPU.
  • the projection data is transferred by two projections to the data buffer 1 from the host CPU.
  • S0p, ⁇ Yp, ⁇ p and ⁇ Xp are respectively transferred to the constant registers 4, 6 and 8 and the ⁇ Xa register 10, and the outputs S0p, ⁇ Yp, ⁇ p and ⁇ Xp are respectively generated therefrom.
  • the outputs S0p, ⁇ Yp, ⁇ p and ⁇ Xp are respectively supplied to the first portion of the reconstructor BPR, and the outputs S0p and ⁇ Xp are supplied to the adder 12.
  • the sum S2p is latched by the constant register 4. Then, the output S1(p+1) is transferred to the second portion of the reconstructor BPR from the constant register 5. Simultaneously, the output S1(p+1) and ⁇ X(p+1) are added to each other by the adder 12. The sum S2(p+1) is latched by the constant register 5. In this manner, the reconstruction starting points Sna of the respective lines for the two projections are sequentially calculated without requiring complex calculation and are sequentially supplied to the reconstructor BPR.
  • the projection data for the next two projections is transferred to the data buffer 1 from the CPU. The above processing is repeated.
  • Selection between the non-duplex processing mode and the duplex processing mode in the constant generating circuit CGC is performed by switching a read-out address range of the ROM sequencer 3 in correspondence to the state of the switch provided in the controller CNT.
  • sequences corresponding to the non-duplex processing mode and the duplex processing mode are respectively stored in the different storing areas.
  • FIG. 5 is a flow chart schematically showing a sequence of the processing of the FRU for the MRI system according to this embodiment.
  • the projection number is 300 and the image matrix is a 512 ⁇ 512 matrix.
  • FIG. 5 and the corresponding description correspond to the non-duplex processing mode. However, each of the descriptions which is inserted between two braces “ ⁇ ”and “ ⁇ ” represents the case of the duplex processing.
  • the word "CPU” means not only the host CPU itself, but includes memories.
  • commands 1 to 3 are supplied to the controller of the FRU from the CPU.
  • the constants for one scanning that is, for 300 projections are transferred to the CGC from the CPU.
  • the command 2 is supplied to the FRU, the projection data for one projection ⁇ two projections ⁇ are transferred to the CGC from the CPU.
  • These commands 1 and 2 enable the back projection processing.
  • the back projection processing for one projection ⁇ two projections ⁇ is performed by the command 3.
  • the processing starts in response to to the command 3
  • the projection data for one projection ⁇ two projections ⁇ is transferred to the BPR from the CGC, and constants for one projection ⁇ two projections ⁇ are transferred to the BPR from the CGC.
  • the back projection processing by the BPR for one projection ⁇ two projections ⁇ is performed.
  • the "back projection processing by the BPR” will be referred to as the BPR processing hereafter.
  • the back projection processing for one projection ⁇ two projections ⁇ by the command 3 is completed.
  • a status flag which represents this completed state is set.
  • the command 2 is supplied from the CPU to the FRU, and during the BPR processing for one projection ⁇ two projections ⁇ , the projection data for next one projection ⁇ two projections ⁇ is transferred to the constant generating circuit CGC. In this manner, the processing by the commands 2 and 3 is repeatedly performed, thereby eliminating a data transfer time from the CPU to the CGC in the back projection.
  • the processing for two projections are performed at substantially the same time, it can be performed in a half period of time for the normal processing (non-duplex processing).
  • duplex of pipe-line processing When duplex of pipe-line processing is adopted, processing efficiency can be considerably improved.
  • This duplex of pipe-line processing can be realized by utlilizing the pipe-line processing according to the present invention.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)
  • Apparatus For Radiation Diagnosis (AREA)
US06/661,459 1983-10-17 1984-10-16 Magnetic resonance imaging system Expired - Lifetime US4620153A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP58193750A JPS6085357A (ja) 1983-10-17 1983-10-17 核磁気共鳴映像装置
JP58-193750 1983-10-17

Publications (1)

Publication Number Publication Date
US4620153A true US4620153A (en) 1986-10-28

Family

ID=16313185

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/661,459 Expired - Lifetime US4620153A (en) 1983-10-17 1984-10-16 Magnetic resonance imaging system

Country Status (2)

Country Link
US (1) US4620153A (enExample)
JP (1) JPS6085357A (enExample)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4721911A (en) * 1985-07-26 1988-01-26 Siemens Aktiengesellschaft Nuclear magnetic resonance tomography apparatus
US4775835A (en) * 1986-03-31 1988-10-04 Kabushiki Kaisha Toshiba Magnetic resonance imaging apparatus including sequence controller
EP0285862A1 (en) * 1987-04-06 1988-10-12 General Electric Company Rapid scan NMR angiography
US4835690A (en) * 1985-11-19 1989-05-30 Picker International, Inc. Integrated expert system for medical imaging scan, set-up, and scheduling
US4860221A (en) * 1985-08-21 1989-08-22 Kabushiki Kaisha Toshiba Magnetic resonance imaging system
EP0335981A4 (en) * 1987-09-30 1990-06-26 Toshiba Kk MAGNETIC RESONANCE IMAGING SYSTEM.
US5206593A (en) * 1990-10-31 1993-04-27 Joel Ltd. Real-time control system for NMR spectrometer
US5233516A (en) * 1987-06-19 1993-08-03 General Electric Cgr S.A. Method for recording movements inside an object and for showing on an image display the effects of these movements
US5304928A (en) * 1991-03-20 1994-04-19 Hitachi, Ltd. Method of magnetic resonance imaging
US5414622A (en) * 1985-11-15 1995-05-09 Walters; Ronald G. Method and apparatus for back projecting image data into an image matrix location
US5483158A (en) * 1993-10-21 1996-01-09 The Regents Of The University Of California Method and apparatus for tuning MRI RF coils
US20040006657A1 (en) * 1995-06-22 2004-01-08 Wagner Richard Hiers System and method for enabling transactions between a web server and an automated teller machine over the internet

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1471531A (en) * 1973-04-25 1977-04-27 Emi Ltd Radiography
US4135247A (en) * 1977-08-15 1979-01-16 Siemens Aktiengesellschaft Tomography signal processing system
US4168435A (en) * 1976-07-19 1979-09-18 N.V. Optische Industrie "De Oude Delft" Method and apparatus for tomography wherein signal profiles derived from an out-fanning beam of penetrating radiation can be reconstructed into signal profiles each corresponding with a beam of parallel incident rays
US4340862A (en) * 1978-12-13 1982-07-20 Picker International Limited Imaging systems
US4446521A (en) * 1980-03-28 1984-05-01 Tokyo Shibaura Denki Kabushiki Kaisha Image reconstruction apparatus and process
US4486708A (en) * 1981-12-21 1984-12-04 Albert Macovski Selective material projection imaging system using nuclear magnetic resonance
US4551680A (en) * 1983-04-21 1985-11-05 Albert Macovski Selective region NMR projection imaging system
US4555760A (en) * 1982-05-12 1985-11-26 U.S. Philips Corporation Method and computer tomography device for determining a tomographic image with elevated resolution

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1471531A (en) * 1973-04-25 1977-04-27 Emi Ltd Radiography
US4168435A (en) * 1976-07-19 1979-09-18 N.V. Optische Industrie "De Oude Delft" Method and apparatus for tomography wherein signal profiles derived from an out-fanning beam of penetrating radiation can be reconstructed into signal profiles each corresponding with a beam of parallel incident rays
US4135247A (en) * 1977-08-15 1979-01-16 Siemens Aktiengesellschaft Tomography signal processing system
US4340862A (en) * 1978-12-13 1982-07-20 Picker International Limited Imaging systems
US4446521A (en) * 1980-03-28 1984-05-01 Tokyo Shibaura Denki Kabushiki Kaisha Image reconstruction apparatus and process
US4486708A (en) * 1981-12-21 1984-12-04 Albert Macovski Selective material projection imaging system using nuclear magnetic resonance
US4555760A (en) * 1982-05-12 1985-11-26 U.S. Philips Corporation Method and computer tomography device for determining a tomographic image with elevated resolution
US4551680A (en) * 1983-04-21 1985-11-05 Albert Macovski Selective region NMR projection imaging system

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4721911A (en) * 1985-07-26 1988-01-26 Siemens Aktiengesellschaft Nuclear magnetic resonance tomography apparatus
US4860221A (en) * 1985-08-21 1989-08-22 Kabushiki Kaisha Toshiba Magnetic resonance imaging system
US5414622A (en) * 1985-11-15 1995-05-09 Walters; Ronald G. Method and apparatus for back projecting image data into an image matrix location
US4835690A (en) * 1985-11-19 1989-05-30 Picker International, Inc. Integrated expert system for medical imaging scan, set-up, and scheduling
US4775835A (en) * 1986-03-31 1988-10-04 Kabushiki Kaisha Toshiba Magnetic resonance imaging apparatus including sequence controller
EP0285862A1 (en) * 1987-04-06 1988-10-12 General Electric Company Rapid scan NMR angiography
US5233516A (en) * 1987-06-19 1993-08-03 General Electric Cgr S.A. Method for recording movements inside an object and for showing on an image display the effects of these movements
US4999581A (en) * 1987-09-30 1991-03-12 Kabushiki Kaisha Toshiba Magnetic resonance imaging system
EP0335981A4 (en) * 1987-09-30 1990-06-26 Toshiba Kk MAGNETIC RESONANCE IMAGING SYSTEM.
US5206593A (en) * 1990-10-31 1993-04-27 Joel Ltd. Real-time control system for NMR spectrometer
US5304928A (en) * 1991-03-20 1994-04-19 Hitachi, Ltd. Method of magnetic resonance imaging
US5483158A (en) * 1993-10-21 1996-01-09 The Regents Of The University Of California Method and apparatus for tuning MRI RF coils
US20040006657A1 (en) * 1995-06-22 2004-01-08 Wagner Richard Hiers System and method for enabling transactions between a web server and an automated teller machine over the internet
US6684269B2 (en) 1995-06-22 2004-01-27 Datascape Inc. System and method for enabling transactions between a web server and a smart card, telephone, or personal digital assistant over the internet
US6694387B2 (en) 1995-06-22 2004-02-17 Datascape, Inc. System for enabling smart card transactions to occur over the internet and associated method
US6745259B2 (en) 1995-06-22 2004-06-01 Datascape, Inc. Open network system for i/o operation including a common gateway interface and an extended open network protocol with non-standard i/o devices utilizing device and identifier for operation to be performed with device
US6850996B2 (en) 1995-06-22 2005-02-01 Datascape, Inc. System and method for enabling transactions between a web server and an automated teller machine over the internet
US6907476B2 (en) 1995-06-22 2005-06-14 Datascape, Inc. Open network system and method for I/O operations with non-standard I/O devices using an extended open network protocol
US7984172B2 (en) 1995-06-22 2011-07-19 Datascape, Inc. System and method for transacting communication over an open network

Also Published As

Publication number Publication date
JPS6085357A (ja) 1985-05-14
JPH0245451B2 (enExample) 1990-10-09

Similar Documents

Publication Publication Date Title
US4620153A (en) Magnetic resonance imaging system
EP0093429B1 (en) Method of and apparatus for enlarging/reducing two-dimensional images
JPH0445689Y2 (enExample)
US4042811A (en) Tomography system having an ultrahigh-speed processing unit
US5275164A (en) Multi-dimensional magnetic resonance imaging method and apparatus for same
US4710716A (en) Slice orientation selection arrangement
US4682289A (en) View interpolation in a tomography system using pipe line processing
EP0412657B1 (en) Imaging apparatus and methods
EP1069533B1 (en) Efficient methods and apparatus for resampling three-dimensional datasets
WO2001075793A2 (en) Fast hierarchical reprojection algorithm for tomography
US5724608A (en) Medical image system using dual address generators to allow CPU accessed three-dimensional body image data in accordance with one-dimensional storage address in dual memories simultaneously
JP2000041978A (ja) フォワ―ドプロジェクション／バックプロジェクションプロセッサ
EP0314790A1 (en) Method of correcting image distortion for nmr imaging apparatus
US4504909A (en) Method of using an array processor for real time processing
EP0504855B1 (en) X-ray computerized tomography apparatus
JPH10137192A (ja) スクリプト又はバーチャルコードを備えた医学的システムアーキテクチュア
JPH06171A (ja) フーリエ変換を用いるｍｒｉ画像のリサイジング方法
US4654797A (en) Computer tomography system wherein preprocessing, convolution and back projection computations are performed prior to external data storage
US5802135A (en) Arithmetic unit for a computed tomography apparatus
EP0294089B1 (en) Data acquisition circuit
US6145026A (en) Parameterizing an I/O interface for substantially writing unlimited data into a buffer and directly writing a determined amount of said data into a computer main memory
JPH11169364A (ja) ２ステップ３ｄラドン逆変換処理方法
JP3285944B2 (ja) コンピュータ断層撮影装置
JP4391214B2 (ja) 磁気共鳴イメージング装置
US5352981A (en) High-resolution image reconstruction method for MRI

Legal Events

Date Code Title Description
AS Assignment

Owner name: KABUSHIKI KAISHA TOSHIBA 72 HORIKAWA-CHO, SAIWAI-K

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:HINO, MASAAKI;REEL/FRAME:004325/0848

Effective date: 19841006

STCF Information on status: patent grant

Free format text: PATENTED CASE

CC Certificate of correction
FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12